GoetzPre-PDR Peer Review October 2013 FIELDS Time Domain Sampler Peer Review Keith Goetz University of Minnesota 1

GoetzPre-PDR Peer Review October 2013 STEREO snapshot 2

GoetzPre-PDR Peer Review October 2013 STEREO snapshots 3

GoetzPre-PDR Peer Review October 2013 STEREO snapshot 4

GoetzPre-PDR Peer Review October 2013 Heritage Time Domain Sampler (TDS) is based on previous instruments –Based most recently on STEREO instrument Gathers impulsive events –Centered peaks –Simultaneous sampling on all channels Smooth activity - new –Fixed sampling rate – 1.92MSa/s –Programmable effective sampling rate –Programmable event duration Events have peaks –After that, flight software rates event based on programmable criteria –Quality can be adjusted – up or down - after the fact –When telemetry is available (nominally to DCB), best event is sent –When memory is needed (for a new event), worst event is deleted Event selection can be based on quality or not – honesty Low rate stream gives peak activity as a function of time 5

GoetzPre-PDR Peer Review October 2013 Analog Inputs Channel 1 (ADCs want 0V to 2V at <=1MHz) –V 1 MF –E PAR MF Channel 2 –V 2 MF –V 3-4 MF Channel 3 –V 3 MF –V 1-2 MF Channel 4 –V 4 MF –B MF SWEAP counts –? Unused –V 5 MF –V 1 REF, V 2 REF, V 3 REF, V 4 REF, V 5 REF –V 1-2 REF, V 3-4 REF, E PAR DC –V 1 DUST, V 2 DUST, V 3 DUST, V 4 DUST, V 5 DUST 6

GoetzPre-PDR Peer Review October 2013 Big Dust 7

GoetzPre-PDR Peer Review October 2013 Dust 8

GoetzPre-PDR Peer Review October 2013 FIELDS/TDS Evolution 9 FIELDS was proposed as a single string instrument Within FIELDS, TDS was proposed as a single science board

GoetzPre-PDR Peer Review October 2013 TDS Evolution In early 2013, Project recognized that FIELDS was central to meeting threshold science – occupying 4 of 9 blocks 10

GoetzPre-PDR Peer Review October 2013 TDS Evolution – System-6 FIELDS then suggested a number of alternatives –increasing reliability Eventually, we settled on System-6 11

GoetzPre-PDR Peer Review October 2013 Configuration 12

GoetzPre-PDR Peer Review October 2013 Configuration at UMN 13

GoetzPre-PDR Peer Review October 2013 TDS Requirements 14 TDS-01 Mission Length –TDS Components must be selected to withstand the environment of SPP for the duration of the mission. TDS-02 Spacecraft Interface Compliance (General) –TDS shall implement the spacecraft interface protocol… TDS-03 Timing from S/C –TDS shall provide latching facility upon detection of the "Virtual 1PPS" S/C timing signal… TDS-04 –Timing from DCB TDS shall provide an electrical interface to the Data Control Board capable of…

GoetzPre-PDR Peer Review October 2013 SWEAP Requirements 15 TDS-05 SWEAP Interface - CDI –TDS shall provide an electrical interface to the SWEAP instrument capable of sending CDI commands, receiving CDI messages: [a] sending Command/Data Interface (CDI) messages to SWEAP; [b] receiving SWEAP status and burst information from SWEAP; [c] sending TDS time-keeping information; [d] sending TDS clock synchronization. TDS-06 SWEAP Interface – Particles –TDS shall provide an electrical interface to the SWEAP instrument capable of: [a] receiving particle count information from SWEAP [b] receiving particle synchronization and state information from SWEAP

GoetzPre-PDR Peer Review October 2013 MAG Requirements 16 TDS-07 MAG Interface – CDI –TDS shall provide an electrical interface to the MAG Electronics capable of: [a] setting control registers [b] receiving MAG Science and Engineering data [c] provide MAG AC heater synchronization

GoetzPre-PDR Peer Review October 2013 AEB Requirements TDS-08 Antenna Electronics Board Interface (AEB) –TDS shall provide an electrical interface to the Antenna Electronics Board capable of: [a] setting Biasing D/A converters and relays [b] reading back the biasing voltages [c] provide DC-DC converter synchronization 17

GoetzPre-PDR Peer Review October 2013 LNPS Requirements TDS-09 Low Noise Power Supply Interface (LNPS) –TDS shall provide an electrical interface to the Low Noise Power Supply capable of [a] setting control registers for Power Control and Housekeeping Channel [b] receiving an analog housekeeping signal [c] provide DC-DC synchronization 18

GoetzPre-PDR Peer Review October 2013 TDS Requirements TDS-10 Time Domain Sampler Control –TDS shall provide electrical interfaces to the Time Domain Sampler data acquisition system capable of: [a] setting TDS instrument modes [b] receiving TDS instrument data TDS-11 TDS Memory Management –TDS shall include memory such that: [a] is capable of storing ~20 TDS snapshot events [b] allows best available event to be sent to telemetry TDS-12 TDS Instrument Calibration –TDS analog science and analog housekeeping conversion coefficients are determined and provided prior to S/C Integration to include gain, phase and timing 19

GoetzPre-PDR Peer Review October 2013 Science Requirements TDS-13 E Signals –TDS shall provide an electrical interface capable of: [a] signal processing and measurement of the low frequency component of E-Field signals TDS-14 E Signals –TDS shall provide an electrical interface capable of: [a] signal processing and measurement of the AC or plasma frequency (ranging to ~1MHz) component of E-Field signals." TDS-15 B Signals –TDS shall provide an electrical interface capable of: [a] signal processing and measurement of the AC or plasma frequency (ranging to ~1MHz) component of B-Field signals (single axis)." TDS-16 Instrument Calibration –TDS shall provide calibration parameters and algorithms so as to allow conversion from telemetry units to physical units (gain and offset per channel) prior to S/C Integration. 20

GoetzPre-PDR Peer Review October 2013 TDS Block Diagram 21

GoetzPre-PDR Peer Review October 2013 TDS FPGA Block - New 22

GoetzPre-PDR Peer Review October 2013 Spacecraft picture 23

GoetzPre-PDR Peer Review October 2013 FIELDS block diagram 24

GoetzPre-PDR Peer Review October 2013 BB2 25

GoetzPre-PDR Peer Review October 2013 TDS – Single Board Data Acquisition System Centers on RTAX4000 FPGA daughter board –Holds all logic, interfaces and LEON 3 processor instantiation TDS event data gathered by 16-bit ADCs at ~2MSa/s –Multiplexed 16-bit data bus Simultaneous acquisition of SWEAP particle counts TDS event data stored directly into dedicated event memory –16MB event SRAM – 8 parts – 512k by 32bits –Circular buffers Processor support –8-bit data bus Local SRAM w/ ECC Local boot PROM (some in FPGA?) Local program EEPROM S/C serial interfaces CDI interfaces to DCB, MAG, SWEAP Device interfaces – AEB, LNPS Mezzanine interface –Diagnostic UARTs 26

GoetzPre-PDR Peer Review October 2013 Issues Design is advanced –Based on earlier implementation –More than usual at this point (PDR) Selected ADC is great – but plastic –A cousin was used on STEREO –Putative parts have been obtained (x100) –Lead has been added –DPA has been completed (x5) well –Radiation and Beam –Up-screening –Backup solutions could be painful in performance and power Overall power –We’re only now getting to good power estimates –Descope alternatives exist LVDS protection solution is still open 27

GoetzPre-PDR Peer Review October 2013 Next Continue development work with BB2 –FPGA –FSW –Spacecraft Emulator –FIGs for DCB, MAG and SWEAP –Ground software Modify existing schematic for ETU Layout ETU 28

GoetzPre-PDR Peer Review October 2013 FIELDS-SWEAP Communication 29

GoetzPre-PDR Peer Review October 2013 Waveform Zoomed 30 Samples Δ t = 500ns CLK ~2MHz V(t) Δ t = 500ns count(t)

GoetzPre-PDR Peer Review October 2013 Waveform Zoomed! 31 Samples Δ t = 500ns V(t) Δ t = 500ns count(t) t = 1,500nst = 2,000nst = 2,500nst = 3,000nst = 3,500nst = 4,000nst = 4,500nst = 5,000ns V = 0mVV = -2mVV = -4mVV = +5mVV = -12mVV = -15mVV = -10mVV = -5mV n = 2n = 4n = 2 n = 7n = 3n = 5

GoetzPre-PDR Peer Review October 2013 Sweep sync 32 Samples Δ t = 500ns V(t) Δ t = 500ns count(t) t = 1,500nst = 2,000nst = 2,500nst = 3,000nst = 3,500nst = 4,000nst = 4,500nst = 5,000ns V = 0mVV = -2mVV = -4mVV = +5mVV = -12mVV = -15mVV = -10mVV = -5mV n = 2n = 4n = 2 n = 7n = 3n = 5 sync(t) t = 2,500ns